406 SEA-SIDE STUDIES. 



Whence, then, is the Sensibility derived? Either we 

 must admit the presence of what cannot be discovered ; 

 or we must admit that a function can act without its 

 organ ; or, finally, we must modify our conception of 

 the relation between Sensibility and the Nervous system. 

 Which of these three conclusions shall we adopt ? 



Not the first : for, to admit the j)resence of an organ 

 which cannot be discovered, even by the very highest 

 powers, although easily discoverable in other animals 

 by quite medium powers, would be permissible only as 

 the last resource of hypothesis, when no other supposi- 

 tion could be tenable. 



Not the second : for philosophic Biology rejects the 

 idea of a function being independent of its organ, since 

 a function is the activity of an organ. The organ is the 

 agent, the function the act — a point to which we will 

 presently recur. 



The third conclusion, therefore, seems inevitable : we 

 must modify our views. But how ? Instead of saying, 

 " Sensibility is a property of nervous tissue," we must 

 say, " Sensibility is a general property of the vital 

 organism luhich becomes sj^ecialised in the nervous 

 tissue in iwoportion as the orga7iis7n itself becomes 

 specialisecV^ 



We have no difficulty in understanding how Con- 

 tractility, at first the property of the whole of the simple 

 organism, becomes specialised in muscidar tissue. We 

 have no difficulty in understanding how Eespiration, at 

 first effected by the whole surface of the simple organism, 

 becomes specialised in a particular part of that surface 



